A generally homemade percussion instrument consisting of crown cap beer bottle tops loosely nailed to a pole (often a broom handle) and a board mounted cross-ways on the pole (the head of the broom), and played by striking the pole on the ground or with a stick, by drawing the serrated stick across the pole, or by shaking the instrument.
Related
Similar words
boozaphone, mendoza/mendozer, monkey stick, Murrumbidgee River Rattler